Add colorama as a conditional dependency for Windows

[abravalheri]

Purpose

As discussed in #609 (comment), when we transitioned from v3 to v4 (and were finally allowed to have dependencies), we forgot to add a conditional dependency on colorama for windows. (And by "we", I mean that it was definitely me that forgot 😅...)

colorama is currently being checked on our termui code.

Approach

• Add colorama as a conditional dependency for windows
  (obs win32 is just the name of the architecture, it does not mean that Python runs on 32 bits. Currently there is no win64, and that would imply in a change in architecture).

[coveralls]

Pull Request Test Coverage Report for Build 6705013379563520

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 97.459%

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Totals
Change from base Build 5267766528704512:	0.0%
Covered Lines:	1710
Relevant Lines:	1744

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💛 - Coveralls